Wikipedia:Reference desk/Archives/Miscellaneous/2020 August 17

= August 17 =

Ship with the world's tallest air draft
My question is simple:

If an engineer was looking to design a bridge over a body of water used for shipping - and he wanted to build it tall enough that every single ship in the world (even an aircraft carrier or the like) could safely pass underneath the bridge fully loaded - how tall above the high-tide mark would the bridge need to be?

To put the question another way, what is the tallest point a ship has ever reached above the waterline?

We have an article on Air draft, but it doesn't seem to contain this information. Can anybody track down an answer? (Maybe also include it in the article, if you're so inclined?) Eliyohub (talk) 16:39, 17 August 2020 (UTC)
 * Just hunting and pecking, the air draft of the cruise ship Oasis of the Seas is 213 feet (64 meters), while the largest air draft of a cargo ship I can find is the Emma Mærsk at 59 meters (193 feet). That doesn't mean those are the largest in the world, just the largest I can find.  -- Jayron 32 16:47, 17 August 2020 (UTC)


 * That article on air draft does mention that 65 m (the height of Storebæltsbroen in Denmark, limiting access to the Baltic Sea) is more or less a standard that they don't exceed. Another candidate is the USS Constitution, according to our article 67 m high. Not entirely clear if that's measured from waterline or from keel. I did have a look at some other tall sailing ships; most are 45–60 m. PiusImpavidus (talk) 19:57, 17 August 2020 (UTC)
 * I don't know where those numbers from our article come from, they are different than what is listed at, which is the reference those are cited to. -- Jayron 32 11:51, 18 August 2020 (UTC)
 * Ships to New York Harbor/cargo part are limited by 69.5/66 meter bridges respectively. Take that Baltic! Sagittarian Milky Way (talk) 18:17, 18 August 2020 (UTC)
 * One option would be a Transporter bridge which could probably have a much higher clearance than a normal bridge, although real examples are only 50m. More practical is perhaps a Swing bridge; no problems with mast height. --TrogWoolley (talk) 22:20, 18 August 2020 (UTC)
 * The only bridge between Manhattan (where cruise ships dock) and the high seas is 13 lanes and has 2.3 cars a second forever (long-term average). The river east of Manhattan does have a lift bridge as that is a more twisty way out, only a few hundred yards wide at minimum (shore-to-shore) and has buttloads of bridges, the first in 1883 (Brooklyn Bridge, 127 feet) Sagittarian Milky Way (talk) 14:49, 19 August 2020 (UTC)
 * Just to clarify, between the Manhattan Cruise Terminal and the sea is only one bridge, being the Verrazzano-Narrows Bridge. At 211 meters above the water, it's got plenty of clearance for all ships passing under it.  The Port of New York and New Jersey, which is where most ocean-going vessels including cruise ships dock in the New York Metro Area, lies along both sides of New York Harbor, which includes the lower Hudson River and Upper New York Bay.  Besides the Verrazzano-Narrows Bridge, the only other bridge along that water way is the George Washington Bridge which is even higher; the only navigation restrictions on the Hudson would be draft restrictions (bottoming out).  This is not necessarily true along other waterways in the New York Metro area, which may have much lower bridges.  -- Jayron 32 15:02, 19 August 2020 (UTC)
 * You've got it backwards, it's the GWB that's lower, 212 feet. Suez canal clearance is even higher than NYC (70 meters), they don't want to be bit in the ass any time soon. Sagittarian Milky Way (talk) 15:25, 19 August 2020 (UTC)
 * Yes, you're correct the GWB is lower; it's 184 m or 604 feet. My bad.  Still more than high enough to let every ship in the world pass.  There is only one current bridge over the Suez, the Suez Canal Bridge, which has a height of 154 m, so shorter than both of the NYC crossings, but still quite high enough for any ship to pass under.  There used to be another, the El Ferdan Railway Bridge, a swing bridge, that is no longer used and is permanently open.  -- Jayron 32 15:37, 19 August 2020 (UTC)
 * You're still looking at tower height, we want clearance below. Sagittarian Milky Way (talk) 15:44, 19 August 2020 (UTC)
 * So to be clear list of bridges in the United States by height shows there's no 211+ meter bridges in NY or NJ. The Verrazzano is at or about 211 meters to the suspension tower, I've been a height of things in NYC buff for 17 years, I would know. Sagittarian Milky Way (talk) 01:22, 21 August 2020 (UTC)
 * AH! Sorry.  My mistake.  Carry on.  -- Jayron 32 12:28, 21 August 2020 (UTC)
 * Tower Bridge has a clearance of 42.5 m at "mean high water spring tide". I'm fairly sure that ships regularly wait for low tide before passing through, but can' says around 2t find a reference. Large cruise liners and tall ships are frequent visitors like this one. Alansplodge (talk) 16:30, 19 August 2020 (UTC)
 * 220ish feet? Sagittarian Milky Way (talk) 01:22, 21 August 2020 (UTC)